Re:. It was tremendously significant to the Allies - but I recall it was also a stroke of luck coupled with a very bad strategic move by the Bismarck's captain, is that right?

Yes, it was a series of lucky bits..

First, a Norwegian member of the underground, saw the newly completed Bismarck steaming north (going up into arctic, to circle round Iceland, and "surprize" convoys by appearing in the mid atlantic) so the british knew were the bismark was, and laid in wait, at the other side of Iceland.

TheHood was there,, and up to the match..Well, not quite... The Hood was sunk by the Bismarck, an breaking all the laws of the sea, they refused to remain long enough to pick up the sailors, since they suspected rightfully, that there were more british and allied ships as back ups on the way.

The Hood had gotten off a few torpedos before being sunk, and while none were enought to sink the Bismarck they did hit one below the water line, and the Bismarck was taking on water. And worse, it had damaged the oil lines, so 1) they were contaminated with sea water, and 2) the back up lines were leaking too, so they were losing oil presure, and could not maintain speed -- since the bismarck was then the fastest thing going, getting away from the Hood, and Allied patrol boats was dependant on speed.

but the bismarck almost made it.. But the captain was convinced he hadn't! So he broke radio silence, and gave away his postition! but the bismarck had moved out of range of all of the british fleet..

a last ditch attempt was made using torpedos mounted on bi-planes, with canvas wings! The bismarck was at the very end of their flying range.. Seas were rough, and droping a torpedo off a airplane as new... There was one direct hit.. it destroyed the rudder, and now, the bismarck was almost a drift..

The admiralty planned to have another attack by the bi-planes, but bits and pieces of the navy moved into place, catching up to the now slow, and rudderless Bismarck the sea men wanted to finish her off, and did.. it was payback for the lost men of the Hood.

and that is my some total of knowledge about the sinking of the bismarck!